In a paper conveying apparatus of an image reading apparatus, image copying apparatus, etc., sometimes a jam occurs when the paper moves along the conveyance path. In general, a paper conveying apparatus is provided with the function of determining whether a jam has occurred by a paper being conveyed to a predetermined position inside the conveyance path within a predetermined time from the start of conveyance of the paper and of stopping the operation of the apparatus when a jam has occurred.
On the other hand, if a jam occurs, a large sound is generated in the conveyance path, so the paper conveying apparatus can determine whether a jam has occurred based on the sound which is generated on the conveyance path and thereby detect the occurrence of a jam without waiting for the elapse of the predetermined time.
A document conveying apparatus comparing sound energy received from at least two microphones and determining whether it is environmental noise, whether two sheets were conveyed, and whether a single sheet was damaged. This document conveying apparatus stops to prevent a document from being damaged when two sheets have been conveyed or a single sheet has been damaged (see PLT 1).